World war 1 notes on the reasons for stalemate on the western front

The reasons for stalemate on the Western Front?
WW1 started as a war of quick lightning thrusts and high mobility, but degenerated into an astonishingly protracted war of static battle lines. The Western Front was the name given to the line of trenches stretching from the Belgium coast to Verdun. Following the Battle of Marne and Aisne of 1914, both sides dug in believing trenches to be temporary. The Front stretched for hundreds of miles, meshed with complex trench systems and barbed wire.
Why Stalemate
The military plans (Schlieffen, XVII...) had established a strict "war by timetabl…